The roof of a residential or commercial building is typically constructed by attaching several roofing panels to the rafters of an underlying supporting structural frame; the panels are most often placed in a quilt-like pattern with the edge of each panel contacting the edges of adjacent panels so as to form a substantially continuous flat surface atop the structural frame.
However, problems with roofs constructed according to this method may present themselves. In particular, small gaps along the edges of adjoining roofing panels remain after roof assembly. Because the roofing panels are typically installed days or even weeks before shingles are installed, it is important to have a panel system that minimizes leakage resulting from exposure to the elements until such time as the roof is completed. To prevent water from leaking through the gaps between panels, it is commonly known in the industry to put a water resistant barrier layer on top of the roofing panels (e.g., felt paper). Accordingly, there is a need in the art for roofing panels, which can be conveniently fit together and yet are constructed to minimize the gaps or allow the gaps to be sealed between adjacent roofing panels to prevent or minimize the penetration of bulk water through the roof as it travels over the roof's surface. It is desirable for roofing panels to shed precipitation, such as rain and snow, during construction so that the interior remains dry. Further, there is a need in the art for roof sheathing panels, which are moisture permeable and create a simplified, safe, and time-saving installation process by means of a surface overlay member or coating permanently bonded thereon.
While it is important that the barrier layer shed bulk water, it should also allow for the escape of water vapor. If the barrier were to trap water vapor in a roof panel, the build-up of moisture could lead to rot or mold growth that is undesirable. As mentioned previously, it is known in the art that substantial bulk water-impermeability of roofing panels may be improved by adding a layer of impermeable material, such as asphalt-impregnated roofing paper or felt over the external surface of the roof panels. However, while this provides additional protection against bulk water penetration, it has the disadvantage of being difficult and time-consuming to install because the paper or felt must be first unrolled and spread over the roof surface and then secured to those panels. Further, the use of a felt paper overlay often results in a slick or slippery surface, especially when wet. Additionally, when the felt paper is not securely fastened to the roof panels or becomes loose due to wind and other weather conditions or because of poor construction methods, the roof system can become very slippery. Accordingly, a worker walking atop the felt paper must be careful to avoid slipping or sliding while thereon. To that end, the present invention provides a panel for a roof sheathing system comprising structural panels, a mass-transfer barrier, and seam sealing means that is advantageously bulk water resistant and that exhibits adequate anti-skid characteristics.
Given the foregoing, there is a continuing need to develop improved panels for roof construction that prevent or minimize the penetration of bulk water, that come pre-equipped with a water-impermeable barrier layer applied during manufacture, and that have a skid resistant surface.